Postpartum blues is the most common postpartum mood disturbance with prevalence estimates ranging from 30% to 75%. Symptoms, which often begin within the immediate postpartum period and remit within days, include mood lability, irritability, tearfulness, generalized anxiety, and sleep and appetite disturbance.

By definition, postpartum blues are transient, mild, timelimited, and do not require treatment other than reassurance

Conversely, postpartum psychosis is a very severe depressive episode characterized by the presence of psychotic features. This condition is the most severe and uncommon form of postpartum affective disorders, with rates of 1 to 2 episodes per 1000 deliveries. The clinical onset is rapid, with symptoms presenting as early as the first 48 to 72 hours postpartum, and the majority of episodes develop within the first 2 weeks postpartum.

Among these conditions is postpartum depression, a nonpsychotic depressive episode beginning in the postpartum period

Postpartum depression is not classified as a separate disease; it is diagnosed as part of affective or mood disorders in both the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).

According to the DSM-IV, postpartum depression is a depressive disorder with onset within the first 4 weeks postpartum. However to be comprehensive in the literature review and to be able to include the best evidence possible, for this practice guideline, postpartum depression is defined as any depressive episode that occurs within the first year postpartum.